Gravity

This book, profusely illustrated with drawing's in the author's famous style, is likely meant for readers of High School age, and older, who are motivated in teaching themselves about science, including its history, and mathematics, the use of which the author develops as a tool when and where needed. One whole chapter is entirely devoted to teaching basic calculus skills. The author's strength as a teacher lies in his ability to treat every exploration in the form of the triad consisting of the physical concepts and phenomena in one corner, the experiments that were done to make discoveries in another and the mathematical tools people developed to learn the most of subsequent investigations, in the third corner. While the author may be described as a theorist who, incidentally, has made significant and wide-ranging contributions by the application of quantum mechanics to nuclear physics, astrophysics and even biology, among others, he includes discussions of groundbreaking experiments, so that the reader learns of their importance and also gets a feeling for the difficulties involved. For example, he describes in detail how Galileo measured time intervals in doing his experiments with falling objects without having the benefit of a modern stop watch. The result is that gravity is a lot more than just Newton's formula F=Gmm'/r^2, which, incidentally, he derives from Kepler's three (experimental) laws. Unfortunately the book is dated in some respects. For example, it makes no mention of the prediction (now considered as a fact) based on solution of Einstein's equations by Schwarzschild and others who showed that massive stars can collapse under the force of their own gravity until even light can no longer escape from them, forming a black hole. In 1961, when the book was written, this concept was still controversial and even Einstein rejected the notion of their existence, which is probably the reason of its omission. The discussion of "anti-gravity" highlights an important property in contrast with the electromagnetic field, which is that the gravitational force between two masses is always attractive. If there were such a thing as negative mass (e.g. if antiparticles had negative mass), then the gravitational force between two particles of opposite mass would be repulsive and, as Gamow points out, Einstein's Principle of Equivalence would be violated. Since experimental evidence overwhelmingly favors the latter, the argument against the existence of negative mass must be considered equally overwhelming. I noticed a mistake in an equation, which is not too serious because that equation was not used in the text. It is the second equation in Fig.29 of the Temple of Gravity, located just above the portal of the temple. This is the differential equation for the motion of a free particle moving in a gravitational field, as derived by Einstein. The error is that the first term should be a second derivative, not first. In the absence of gravity the Christoffel symbol, indicated by the brackets {}, vanishes ({...}=0) in which case the solution should be straight lines in space-time (within the light cone of the source), which the equation shown does not have. Gamow has been ridiculed for misrepresenting medieval ideas of the shape of the Earth. I believe that his description of that is quite adequate. One may refer to the Journal of Columbus, written during his first voyage to America, as described, for example by Joseph Campbell who asked just that question ("The Impact of Science on Myth", 1961). He describes Columbus' ideas as roughly being those of the poet Dante's "Inferno", citing passages from the Journal to support that. Unfortunately, Columbus' original Journals have been lost for centuries and what we know comes from second hand sources. In addition, while Columbus was possibly without equal as navigator, he was ignorant in other matters, and cannot be trusted of representing Europe's "elite".

I expected that this book would be a nice present for a high school student and it surely fits that bill. What I did not expect was that it would also be useful to college and perhaps even graduate students. Gamow was an important physicist, with many contributions to the development of quantum mechanics. He was also the author of several general interest science books, such as this one. The book begins with two chapters devoted to gravity as seen by Galileo and Newton and a chapter discussing the elements of calculus. These chapters are great for any interested high school student. They are clearly written and should be easily understood at that level. The calculus chapter is nice in that it derives calculus in a practical manner, without the rigorous proofs that tend to bedevil students and make them hate math. The first three chapters, while interesting, have little to offer to a college student, let alone to a graduate student. This changed in the next three chapters, which cover planetary orbits, the tides and celestial mechanics. These chapters are not meant to be rigorous or complete treatments, but they should be of some interest to college students as well as providing an understandable treatment for those with less schooling. The planetary orbit chapter covers, among other things, the precession of earths orbit, a topic generally only covered in an advanced mechanics course, typically taught as an upper level college or graduate school course. The treatment is nonmathematical and is definitely not rigorous, but it is much clearer than the presentation that is given in some advanced mechanics books, such as Goldstein's "Classical Mechanics". It has a nice diagram showing the right hand rule and the origin of precession, and while you cannot solve any problem using this presentation, it is a nice adjunct to the mathematical presentations given in an advanced mechanics book. The chapter on the tides is also very interesting, as it clearly shows, via a nice diagram, the origin of the two tides per day. There is also a nice, easily understandable discussion of the influence of tidal forces on slowing down the rotation of the earth and the effect that this has on the earth/moon system and why the conservation of angular momentum causes the distance of the moon to the earth to increase and its rotational speed to decrease. The chapter on celestial mechanics is also devoid of any mathematics, but is full of interesting facts concerning the complexity of earth's orbit due to the influence of all of the bodies in our solar system and the effect that this has on the climate of the planet. In these three chapters Gamow succeeds in providing information that would be interesting to an advanced college student, while still being able to hold the interest of a high school student. The rest of this short book is devoted to the theory of gravity, from Newton through Einstein and beyond. The chapter on "escaping gravity" describes

Had always heard that Gamow was quite the character. Like Feynman, his ability to distill intimidating concepts down to down to earth (npi) analogies is admirable. Recommend this one (originally written in the early 1960's) to anyone wishing to better understand physics, from Ptolemy through Einstein.

George Gamow was a leading scientist of the 20th century, a man who's name frequents the pages of modern-day science. One of the great services offered by Dover Books is the manner in which they have made timeless books by the world's great scientists available at a reasonable price. I consider it remarkable that, for a few dollars, I could sit at Gamow's feet by reading "Gravity." This is a short book, barely 150 pages long. Written in the second half the 20th century (1960s) it doesn't have any new or particularly earth-shattering information, but information content isn't always the best way to measure a book; there's the delivery, too. And this book, this little gem, has one of the best deliveries I've seen. That's what I appreciated most about "Gravity," the nuances of Gamow's writing and explanatory style. Several weeks before I found Gamow's book in the bookstore, I'd planned a solo kayak trip down the Columbia River, from the town of Saint Helens to the Pacific Ocean. I was looking for something to read during breaks, and in the evening. This is an ideal book for leisure reading, it's not too involved, has very little mathematics, and yet has enough intellectual content that it leaves you feeling accomplished after an hour or two of study. If you've ever picked up a copy of Scientific American magazine and read some of the articles, that'll give you a pretty good idea of what's in this book. In fact, some of the material in the book is based on articles written by Gamow for Scientific American. My copy, stained with river water, has bleached, tattered, dog-eared pages. There's a short (6 pages) but interesting biography at the beginning of the book, followed by a preface to the Dover edition, followed in turn by Gamow's preface to the original edition. I enjoyed this introductory material for the light it shone on Gamow's life. I was humbled by the fact that, while I considered my trip down the Columbia River to be of some merit, Gamow had the nerve to attempt (unsuccessfully) escaping from the Soviet Union by paddling a kayak 170 miles across the Black Sea to Turkey. The first four chapters of Gamow's book follow the same outline used by my high school physics teacher, Mr. Lewis. The first chapter, titled "How things fall" is a historical recounting of Galileo, the tower of Pizza, and balls rolling on ramps, along with some stinging insight into the history of human thought. I particularly liked this commentary from Gamow: "For centuries Aristotelian philosophy and scholasticism dominated human thought. Scientific questions were answered by dialectic arguments (i.e. by just talking), and no attempt was made to check, by direct experiments, the correctness of the statements made." Galileo, of course, dispatched the dialectic arguments by conducting experiments, and in the process helped to establish the core scientific ideas of experimentation and observation. Following tradition Gamow explains gravity by tracing hi

A lovely reprinted Dover edition of a peral from Gamow. The original 1962 edition has been out of print for a number of years. This 2003 edition has added commentary and a fascinating bio of Gamow. He was born in Odessa, in what was then Russia, --before the Soviet Union. The story of his escape to the West is straight out of a thriller. Only it is real! Gamow was referred to by a journalist, some time during the Cold War, as "the only scientist in America with a real sense of humor". He can take the most technical stuff and make it simple. Fun too! The book:--Intellectual treats, whimsy, but deep. Illustrated with lovely drawings by Gamow himself. Much of it can be understood by a child, and other parts might require a little concentration. All of it is great fun. The author Gamow started in nuclear physics, during the Golden Age of Physics, worked with Niels Bohr, then later in the US, on the Manhattan Project during WWII, and after the war, he was professor in Boulder Colorado. He has a building on campus named after him! The books he wrote are pearls, and they have been equally popular with my parent's generation as with mine. Luckely some have been reprinted! Other Gamow titles: Biography of Physics, Atomic Energy [dedicated to the hope of lasting peace], Physics of the Strapless Evning Gown,...We are lucky that Dover has reprinted some of them. Gamow's list of scientific accomplishments includes a 1948 landmark paper on the origin of chemical elements, the Big Bang model, and later work with F. Crick on DNA and genetic coding.-- Do more Gamow editions, Dover!